The sacroiliac (SI) joint is the juncture between the sacrum at the base of the spine and the ilium of the pelvis. The SI joint is a synovial joint in which the sacral surface has hyaline cartilage that moves against fibrocartilage of the iliac surface. The SI joint has irregular elevations and depressions that produce interlocking of the two bones.
Disorders of the SI joint can cause low back and radiating buttock and leg pain. Pain associated with the SI joint can be caused by traumatic fracture dislocation of the pelvis, degenerative arthritis, sacroiliitis, or other degenerative conditions. Contributing factors include post-traumatic injury, accelerated wear/instability after lumbar fusion, post pregnancy pain/instability, and longer life span combined with a more active lifestyle in many patients.
The SI joint is increasingly being recognized as a pain generator as SI joint degenerative disease and instability are being diagnosed and treated more commonly. It is estimated that disorders of the sacroiliac joint are a source of pain for millions of people suffering from back and radicular symptoms.
Surgical treatment of these disorders includes stabilization and/or arthrodesis. Fusion of the SI joint can be accomplished by several different conventional methods encompassing an anterior approach, a posterior approach, and a lateral approach. These procedures typically involve fixation of the sacroiliac joint by placement of one or more trans-sacroiliac implants or by placement of implants into the S1 pedicle and iliac bone.
While these methods have been utilized for fixation and fusion of the SI joint over the past several decades, in certain circumstances challenges with respect to the fixation and fusion of the SI joint may remain unresolved. Many of the SI joint fusion procedures on the market today fixate the SI joint from a challenging lateral approach. Minimally invasive procedures such as these are can be technically difficult requiring extensive surgical training and experience and may result in a substantial incidence of damage to the lumbosacral neurovascular elements. Furthermore, the lateral approach to the SI joint often fixates the joint with multiple implants that go across the joint, not offering a true fusion approach into the SI joint.
Additionally, current techniques and instruments typically allow for either fixation or fusion and thereby do not resolve both issues. Procedures are often performed without adequate removal of the articular joint surfaces or preparation of cortical bone and thereby do not always address the degenerative condition of the SI joint.
Failure to sufficiently stabilize and fuse the SI joint with the implant structures and methods may result in a failure to relieve the condition of the SI joint being treated, leading to continued or recurrent SI joint pain and instability requiring additional surgery.
It would therefore be desirable to provide improved methods, systems, and devices that address at least some of these issues.